Power-drill.



` D. L. MQPARLANB.

l POWER DRILL. APPLICATION riLBD 1111111.21, 1907.

Patented May 30, 1911.

'4 SHEETS-BHEET 1.

@vi/immo@ Patented May 30, 1911,

4 SHEETS-SHEET 2.

D. L. MUPARLANE. POWER DRILL. APRLIUATION FILED 1411.11.21, 1907.

wvawfof n. L, MOPARLANE.

POWER DRILL.

APPLICATION Hmm 11113.21, 1907.

Patented May 30, 1911.

4 SHEETS-SHEET a.

D. L. MUFARLANE.

POWER DRILL.

APPLICATION FILED MAB.. 21, 1907.

menten May so, 1911.l

4 SHEETS-amm 4.

DUNCAN LAREN MOFARLANE, OF VICTOR, COLORADO.

POWER-DRILL.

Specification of Letters Patent.

Patented May ao, 1911A` 'Application led March 21, 1907. Serial No. 363,640.

To all whom it may concern:

Be it lznownthat I, DUNCAN L. MCFAR- LANE, a citizen of the United States, residing in Victor, in the county of Teller and State of Colorado, have invented certain new and useful Improvements vin Power-Drills, of which the following is a specification.

My invention relates to power drills or hammers of the class in which a pistonis reciprocated by a motive fluid such as oompressed air or steam, withina cylinder to which the motive fluid is admitted and from which it passes to the interior of the piston which it drives and from which it is ex- 15 hausted at the end of its forward stroke, such piston being arranged to strike a drill or other'tool at the end of its forwardmovement.

The object of my invention is to improve generally the construction of such mechanism and to employ such mechanism in connection with feeding mechanism which is operated by the motive fluid; the admission of the motive fluid to the feeding mechanism, and also to the piston, being so regulated by a valve that the motive fluid may, if desired,

Abe admitted simultaneously to the feed mechanism and to the piston, or it may be admitted to either of these separately, such Valve being' provided with means whereby the motive fluid may exhaust from the feed mechanism if desired.

The cylinder has at one end an expansion chamber and at the opposite end an exhaust chamber, and has also a chamber of less diameter between the expansion and exhaust junction with the expansion chamber.

chambers provided with a shoulder at its T 1e bore of the piston is enlarged at its rear` end and is formed with ports for admission of the. motive fluid'while the piston is in the expansion chamber and for exhaust when the piston 4projects into the exhaust chamber. The piston has an annular shoulder in rear of the ptrts between. which and the shoulder inthe `cylinder some of the motive 'Huid is caught and compressed on the forward movement of the piston, the arrangement being also such that the supply of the mot-ive fluid to the -cylinder and to the interior of the piston is entirely out offfor a 4'-'fportion of the forward stroke of the piston whereby the motive fiuid is put under high compression in a space ,between the two shou1ders,"above mentioned, which, at 'that 4 time, has no communication with either the admission or exhaust ports. An annulai` groove is formed around the piston at the outer ends of the admission ports thereof whereby the entrance to the interior of the piston ofthe motive fluid is facilitated and likewise its exhaust is made more speedy and complete.

In the accompanying drawings-Figure l shows a side elevation of a power drilling apparatus embodying my improvements. Fig. 2 is a plan View of the same. Fi'g. 3

shows a vertical section of the feed mechay lcentral section of the reciprocating piston,

its cylinder and certain parts connected therewith, the piston being in its real-most position.y Fig. 5 is a similar view with the piston in its forward position. Fig. G shows a transverse section on the line a-a of Fig. 4. Fig. 7 shows a transverse section on the line b-b of Fig. 4. Fig. 8 shows a transverse section on the line c-0 of Fig. 4. Fig. 9 shows a transverse section on the line (Zmcl of Fig. 4 through the valve mechanism. Fig. 10 shows a vertical section through the valve mechanism with the valve in 4position to shut olf theI supply to the feed mechanism. Fig. 11 shows a side elevation of the iston. Fig. 12 shows a Vtransverse sectionyof tile piston on the line e-e of Fig. 11. Fig. 13 shows a vertical central section of a modified form, of apparatus. Fig. 14 shows a side elevation of the valve employed in this modification, and Fig. 15 shows a transverse section on the line 15-15 of Fig. 13.

Referring to Figs. 1 to 12 inclusive, the power cylinder 5, as shown, is formed with an expansion chamber 6 and an exhaust chamber 9 between which is an intermediate chamber .7 of less diameter than either of the other chambers. The exhaust chamber has an exhaust port 10 with which communicates a pipe 1I which may be threaded, as shown, to receive a plug if desired. In the outer portion of t-he exhaust chamber is a plug 12 having exit ports 13 leading toward the working part of the drill 14 which extends throughl a suitable opening in the plug and projects into the exhaust chamber in position to receive blows/from the reciprocated piston. As shown in Fig. 8, the inwardly projecting portion' of the drill 14 is square and fits a square opening in the plug 12. The opposite end of the cy inder 5 is connected `by screw threads 2'with a coupling 1 to which it may be locked by a key 3. The rear end of the expansion chamber 6 is closed by a diaphragm fitting a shoulder 4 in the coupling and between which and the adj acent face of thecoupling there .is a space 17 which communicates by way of a passage 1G in the wall' of the cylinder 5 with the admission valve, hereinafter referred to, and also by means of a passage 19 in the coupling with the interior of a hollow rod 41 secured to the coupling at 18 and extending into a cylinder 40, as shown in Fig. 3. This cylinder carries a pin 4Qa on its outer end which is adapted to be placed in contact with some much larger diameter at the rear. The rear' r rigid surface to form an abutment or brace for the apparatus when in operation. l'Ihe rear end of the hollow rod 41 is provided with a piston head and packing 42al and the arrangement, as clearly indicated in Fig. 3, is such that if a motive fluid be admitted through the hollow rod 41, the cylinder 40 and the 'pin 40EL carried thereby will be forced rearward, or the rod 41 andthe parts connected therewith will be forced forward. In this way the drill may be fed or pressed to its work. The piston 20 is made hollow for the greater portion of its length but has a solidstriking head 25. The forward and middle portion 22 of the bore of the piston is of comparatively small-diameter but itis enlarged into an expansion chamber' 21 of portion 5a of the piston surrounding the expansion chamber l21 is of such diameter as to t snugly the walls of the chamber 6 as it reciprocates back and forth. The middle and forward portion of the piston is of considerably smaller diameter, fitting snugly the walls of the chamber 7, thus form-ing a shoulder 26, as indicated in Fig. 4, which coperates with a shoulder 8 at the junction of the forward end of the chamber 6 with the chamber 7 in the manner hereinafter described.

Near. its forwardend but some distance in rear thereof, the piston is formed with radial admissionports 23, which communicatev with a groove 24 in turn communicatingwith the space 27- in the expansion chamber 6 surrounding the forward portion of the pist-on. To this space 27 the motive fluid is admitted through a port 32 leading from a valve 31 in a valve casing 30ste which the motive fluid is admitted. The valve 31 controls the admission of the motive fluid to the space 27 and also to the conduit 33 leading to the passage-16 that is in communication with the feed mechanism. The valve 31 is chambered at 31a in such manner, as clearly indicated in Fig. 4, that the motive fluid may be admitted to the feed mechanism and to the space 27 of the expansion cylinder simultaneously. 4By reversing the position of the valve, in the manner indicated in Fig. 10, them'lmission of the motive fluid tothe feed mechanism may be entirely cut off and. at

this time the motive fluid is exhausted froml the feed mechanism through a passage 30 y may remove this pressure, which is especially desirable when cutting outribs` from adefective hole. which it may be conveniently operated.

In Fig. 4 the piston is shown in its rearmost position. The motive fluid enters thc space 27, which it fills, and also passes to the interior of the piston, which latter lmoves forward until the admission port-s 23 pass into the chamber 7. complished, the admission of the motive fluid to the interior of the piston is stopped, but there is yet no exhaust and the motive fluidY is still admitted to the space 27 between the shoulders 8 and ,26. As the piston moves forward the ports 23 open to the ex- The valve has a handle 34 by i As soon as this is acn hausti'chamber 9 and the expanded fluid'A rushes out through the chamber 9 and through the passages 13 and blows away chips, etc., around the drill. Soon after this, the enlarged portion 52L of the pist-onv being at this time no communication either with the exhaust or with the admission ports. Immediately after this, the piston strikes a blow on the drill and the compressed iluid between the shoulders 8 and 26 obtains such "a tension that it moves the piston rearward until it assumes the position shown in Fig. 4 when the operations above described will be repeated.

The groove 24, before referred to, enables the motive fluid to more readily enter the admission ports 23 and to more 'quickly exhaust `therefrom. yThis grooye also provides additional'space for entrapping the motive fluid which is carried with the piston and exercises its expansive force even while the grooved portion of the piston is in the chamber 7.

In Figs. 13, 14, and 15 I have shown a modification. In Fig. 13, the coupling 1, as shown, carries the valve mechanism. The valve 50 is of the form shown in Fig. 14. It is arranged in a suitable valve seat in which it turns. It has a port 50a adapted to communicate with the entrance port 51 for the motive fluid, and also with a port 59 leading to the feed mechanism and a port 52 is so arranged that when admission of the.

motive fluid to the feedy mechanism is out H, the motive fluid may exhaust from the feed mechanism. In other respects the ap-y paratu-s is the same as that before described.

I claim as my invention In a device of the'class described,l a cylinder having spaced expansion and exhaust chambers anda connecting passage between n the chambers, the passage being of less diameter than thechambers; a hollow piston fitting closely' in the ex ansion chamber and provided with a re uced end fitting closely in the, passage but spaced V:from the wall of the expansion chamber, there being an inlet port to the expansion chamber,- Which port the piston is adapted to close; the bore of the piston being enlarged adjacent one-end of the piston, and being contracted inthe reduced end of the piston; there beine' a circumscribing, superficial groove in t e reduced end of the piston, and an inlet port leading from said groove into the contracted portion of the bore of the piston, thepiston in its forward movement positioning the inlet port of the piston alternately 1n the passage and in the exhaust chamber, to close the port in the one instance, and to open it in the other, the closure of said port and the closure of the inlet port to the expansion chamber serving to confine a portion of the actuating fluid in the expansion chamber for compression, 'to secure a return of the piston.

In testimony whereof I have hereunto set my hand in presence of two subscribing Wit-- DQSSGS.

DUNCAN LAREN MCFARLANE. l

Witnesses:

WILLIAM BROWN, ISAAC M. I-IENNEY 

